IL9 and rheumatoid arthritis: In RA patients, the positivity for Flt3L was associated with IL-13, IL-1β, granulocyte–macrophage colony-stimulating factor, IL-1 receptor agonist, IL-6, and IL-9 (P < 0.01 for all) and with IL-2 and IL-10 (P < 0.05 for both) after corrections for multiple comparisons.